Condensed Consolidated Statements of Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Series F Preferred Stock	Series G Preferred Stock	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Retained Earnings [Member] Cumulative Effect, Period of Adoption, Adjustment	Retained Earnings [Member] Series F Preferred Stock	Retained Earnings [Member] Series G Preferred Stock	Treasury Stock, Common	Accumulated Other Comprehensive Income (Loss), Net of Tax
Beginning Balance at Dec. 31, 2021	$ 3,438,325				$ 145,037	$ 937	$ 1,108,594	$ 2,333,288				$ (126,951)	$ (22,580)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	165,564							165,564
Other comprehensive (loss), net of tax	(458,752)												(458,752)
Common stock dividends and equivalents	(107,620)							(107,620)
Preferred stock dividends			$ (3,938)	$ (3,656)						$ (3,938)	$ (3,656)
Issued in business combination	5,180,124				138,942	891	5,040,291
Stock-based compensation	30,469						419					30,050
Exercise of stock options	497						(451)					948
Common shares acquired from stock compensation plan activity	(21,095)											(21,095)
Common stock repurchase program	(222,130)											(222,130)
Ending Balance at Jun. 30, 2022	7,997,788				283,979	1,828	6,148,853	2,383,638				(339,178)	(481,332)
Beginning Balance at Mar. 31, 2022	8,177,135				283,979	1,828	6,129,440	2,276,875				(239,264)	(275,723)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	182,311							182,311
Other comprehensive (loss), net of tax	(205,609)												(205,609)
Common stock dividends and equivalents	(71,386)							(71,386)
Preferred stock dividends			(1,969)	(2,193)						(1,969)	(2,193)
Stock-based compensation	21,466						19,517					1,949
Exercise of stock options	86						(104)					190
Common shares acquired from stock compensation plan activity	(2,128)											(2,128)
Common stock repurchase program	(99,925)											(99,925)
Ending Balance at Jun. 30, 2022	7,997,788				283,979	1,828	6,148,853	2,383,638				(339,178)	(481,332)
Beginning Balance at Dec. 31, 2022	$ 8,056,186	$ (4,245)			283,979	1,828	6,173,240	2,713,861	$ (4,245)			(431,762)	(684,960)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible Enumeration]	Accounting Standards Update 2022-02
Net income	$ 455,972							455,972
Other comprehensive (loss), net of tax	(33,863)												(33,863)
Common stock dividends and equivalents	(139,818)							(139,818)
Preferred stock dividends			(3,938)	(4,387)						(3,938)	(4,387)
Stock-based compensation	25,812						(20,501)					46,313
Exercise of stock options	1,723						(2,026)					3,749
Common shares acquired from stock compensation plan activity	(15,404)											(15,404)
Common stock repurchase program	(58,312)											(58,312)
Ending Balance at Jun. 30, 2023	8,279,726				283,979	1,828	6,150,713	3,017,445				(455,416)	(718,823)
Beginning Balance at Mar. 31, 2023	8,294,294				283,979	1,828	6,137,743	2,856,745				(397,981)	(588,020)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	234,968							234,968
Other comprehensive (loss), net of tax	(130,803)												(130,803)
Common stock dividends and equivalents	(70,106)							(70,106)
Preferred stock dividends			$ (1,969)	$ (2,193)						$ (1,969)	$ (2,193)
Stock-based compensation	14,166						12,970					1,196
Common shares acquired from stock compensation plan activity	(319)											(319)
Common stock repurchase program	(58,312)											(58,312)
Ending Balance at Jun. 30, 2023	$ 8,279,726				$ 283,979	$ 1,828	$ 6,150,713	$ 3,017,445				$ (455,416)	$ (718,823)